Fine powder of an acrylonitrile-type polymer and method for its production

摘要

A fine powder of an acrylonitrile-type polymer having a copolymerized acrylonitrile content of at least 95% by weight, containing substantially no sulfonic acid groups and having a reduced viscosity of from 1.0 to 8.0, a volume average particle size of from 1 to 5 mu m and a content of particles having a size exceeding 8 mu m being at most 0.05% by number, may be produced by aqueous suspension polymerisation followed by pulverisation e.g. using an air jet current. The powder is useful as a substitute for inorganic fillers, e.g. in electrostatic recording media or in coating materials.